6th Gen. Civic Gas Mileage

[commercetx]

6th Gen. Civic Gas Mileage

This question is for those who have cold air intakes, header, & exhaust.

Just wondering about how many miles to the 11.9 gallon tank people are getting with their 6th gen. (99-00) Civic
[CITY DRIVING}?

Do you put your foot in it?

What kind of gas do you use?

What would cause a car to start getting bad gas mileage (O2 Sensor, vacuum leak, Catalytic Converter, etc.)?

[melayanton]

I drive fast everywhere and get 25-30 MPG in my hatch and my wife gets 30-35 MPG in her civic, both 99's. Anything that causes the car to not go into closed loop will decrease fuel mileage. Also things like low tire pressure, wider tires and various other chassis problems! Do you have cx, dx, lx? Is your check engine light on?

[commercetx]

These are all the modifications that I have done that I think might affect my gas mileage. I know a lot of these mods add a lot of weight. Modifications: 17x7 Velox VX-8 Gun Metal w/205/40/17's, Ground Control Adjustable Coil-Overs w/Eibach Springs, Ingalls Camber Kit, Front & Rear Upper & Lower Tie & Strut Bars, Weapon R Intake w/K&N Air Filter, DC Sports 4-2-1 Ceramic Header, Borla Boomer Blow Muffler, & Short Shifter. Car was stripped down to just the dash. From the dash back was Extreme Dynamated. Used expanding foam in the trunk lid & pillars Full Size Optima Yellow Top in factory location with 180 amp alternator. My Catalytic Converter has been giving off a rotten egg smell lately. I get around 400 miles to the tank during highway driving. My check engine was on due to I had put a screw through the air fuel mixture valve on the top side of the fuel tank but I had it replaced at the dealership. I was still getting about 200 miles a tank before I had that piece replaced.

Thanx

p.s. I have a Civic Wings West Avenger Body Kit for the 99-00 Coupe for sale. Bought it off ebay but had some unexpected bills come up that same day. Needs to be body shopped due to multiple paint jobs and fitment. $400 for front, rear, 7 sides.

[crucifudge]

i got a del sol, but for referance i went from 38 mpg to 39 mpg after intake and exaust. But in reality i get less, i floor it everywhere now, it sounds so pretty.

[melayanton]

The rotten egg smell is a good indicator of your car running rich. Even with all that stuff in your car I would still have to say you should be above 25 MPG. I would check to make sure the cooalnt temp sensor is within specs (sorry but I dont know the specs off the top of my head) and check the fuel pressure. A while back the fuel pressure regulator on my hatch started going bad and it was about 10 Psi over spec, I was getting about 23-25 MPG. I just added a B&M adjustable and my mileage went back to normal.